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0.4.31 • Public • Published


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[!NOTE] This is one of 189 standalone projects, maintained as part of the @thi.ng/umbrella monorepo and anti-framework.

🚀 Please help me to work full-time on these projects by sponsoring me on GitHub. Thank you! ❤️


Minimal, rational & TypeScript-friendly test runner, result export as CSV/JSON, watch mode, file fixtures.


ALPHA - bleeding edge / work-in-progress

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yarn add @thi.ng/testament

ESM import:

import * as test from "@thi.ng/testament";

Browser ESM import:

<script type="module" src="https://esm.run/@thi.ng/testament"></script>

JSDelivr documentation

For Node.js REPL:

const test = await import("@thi.ng/testament");

Package sizes (brotli'd, pre-treeshake): ESM: 1.09 KB



The library includes a CLI runner to execute tests in various files once, or watch them for changes and then re-execute any changed files. Options and file paths can be given in any order.

testament --help

# Usage: testament [opts] path1 [path2...]
# Options:
# --all, -a        Run all tests (don't stop at 1st failure)
# --exclude, -e    Exclude path prefix (multiple)
# --csv            Export results as CSV
# --json           Export results as JSON
# -o               Output file path for exported results
# --timeout, -t    Set default timeout value (milliseconds)
# --watch, -w      Watch given files/dirs for changes
# --help, -h       Print this help and quit

Note: The CLI tool respects the NO_COLOR convention.

Result exports

Test results can be exported in CSV or JSON formats. To include failed tests, make sure you include the --all/-a CLI flag. If no output file (-o) is given, the results will be written to stdout

testament --all --csv -o results.csv test

testament --all --json -o results.json test

The following details are recorded per test case:

  • group: Parent group ID/title
  • title: Test title/descriptor
  • time: Time taken (incl. retries) in milliseconds (rounded)
  • trials: Number of trials taken
  • error: Error message, failure reason


Generated API docs

Groups of test cases can be specified via group(). The tests are NOT executed immediately until execute() is being called (done automatically when using the CLI wrapper). All tests within the group will share the (optionally) provided configuration options (which themselves will be stubbed using GLOBAL_OPTS).

If a test is async, use the passed TestCtx handlers (esp. done() and setTimeout()) to ensure timeouts and any errors or test failures are handled properly.

If a test case function makes use of the provided TestCtx arg in any way, it MUST call done(), since testament assumes it is an async case.

Any uncaught errors thrown in the group's lifecycle handlers will not be caught by the group wrapper either (In fact, they will be caught, but then re-thrown...). Furthermore, if the exit option is true (default), any uncaught error will cause the entire process to terminate (unless running a browser).

See docs for full options

import { group, execute } from "@thi.ng/testament";
import { assert } from "@thi.ng/errors";

// register group of test cases
    add: () => { assert(1 + 1 === 2); },
    sub: ({ done, setTimeout }) => {
      setTimeout(() => { assert(3 - 1 === 1); done(); }, 50);
  // shared options for all cases in the group
    maxTries: 3,
    timeOut: 100,
    beforeEach: ({ logger }) => logger.info("before"),
    afterEach: ({ logger }) => logger.info("after"),

// only needed if NOT using the CLI runner
const results = await execute();


If this project contributes to an academic publication, please cite it as:

  title = "@thi.ng/testament",
  author = "Karsten Schmidt",
  note = "https://thi.ng/testament",
  year = 2021


© 2021 - 2024 Karsten Schmidt // Apache License 2.0

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